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J Bride

Publications and source records attributed to J Bride.

12 recordsLinked to original sources
PubMed1992

Immunocytochemical localization of insulin-related peptide(s) in the central nervous system of the snail Helix aspersa Müller: involvement in growth control.

1. The presence of insulin-like substances has been demonstrated by immunocytochemistry in the central nervous system of the snail Helix aspersa. 2. The immunopositivity has been observed especially in the large perikarya of the mesocerebral green cells [the cerebral green cells (CeGC) stained in green by the alcian blue:alcian yellow technique]. 3. The removal of either the mesocerebrum or the CeGC stops the growth of the snail and induces the increase of the glycogen content in the mantle edge. 4. Our results show the existence of insulin-like material in the neurosecretory cells. Previous data having demonstrated the presence of specific binding sites to insulin in the cephalic ganglia of Helix aspersa, one may suggest that insulin could play a neuromodulatory or a neurotransmittory role in the central nervous system and might control the growth.

Animals↗
PubMed1992

Serum-free culture of stromal and functionally polarized epithelial cells of guinea-pig endometrium: a potential model for the study of epithelial-stromal paracrine interactions.

Stromal and glandular epithelial (GE) cells were isolated from guinea-pig endometrium and growth to near confluency (6-8 days) in primary culture on plastic surfaces in a serum-supplemented medium (SSM). The stromal cells were subcultured on plastic dishes and maintained for 72 h in SSM. Then SSM was replaced by a chemically defined medium (CDM) and the stromal cells grown to confluency (5-7 days). The GE cells were subcultured in CDM, on a basement membrane matrix (Matrigel) applied to permeable Millicell-PC filters, and grown to confluency (5 days). Homogeneity of the subcultured endometrial cell populations was ascertained immunocytochemically. The filter-cultured GE monolayers were polarized morphologically, and displayed epithelial-specific specialized structures. These monolayers had functional tight junctions as verified by a measurable transepithelial resistance. The subcultured cell populations were distinguished by an analysis of their cellular and secretory proteins after labelling with [35S]-methionine and analysis by polyacrylamide gel electrophoresis. The filter-cultured GE monolayers allowed identification of the proteins released vectorially in the apical or the basal secretory compartment, thus demonstrating the functional polarization of GE cells in this bicameral culture system. Within the defined conditions of this culture system, the paracrine factors released by the two endometrial cell populations as well as the interplay of stromal-epithelial interactions and ovarian hormones could be investigated.

Animals↗
PubMed1992

Progesterone control of fibronectin secretion in guinea pig endometrium.

Immunohistochemistry with a polyclonal antibody raised against human plasma fibronectin (Fn) was used to determine the localization of Fn in endometrial sections of guinea pig uteri isolated at the first, fourth, sixth, or tenth day of the estrous cycle. Immunoreactive Fn was constantly visualized in the endometrial stroma but absent from the epithelial layer. Fn was detected in the uterine lumen on the first or fourth day of the estrous cycle and was absent from the other sections. To determine the origin of this luminal Fn the ability of subcultured endometrial cells to produce Fn was tested, and the hormonal regulation of Fn secretion was studied. Cells were treated by estradiol alone or in association with progesterone, progesterone alone, or untreated. Whatever the hormonal treatment, stromal cells constantly secreted immunoreactive Fn into the culture medium. In the same way, the amount of Fn synthesized and basally secreted by epithelial cells was not affected by any hormonal treatments. However, Fn was found in the apical secretions of the untreated or estradiol-treated epithelial cells but was undetectable in the apical compartment when the epithelial cells were treated by progesterone alone or in association with estradiol. These results indicate that Fn is constitutively secreted by stromal cells and that subcultured epithelial cells of guinea pig endometrium secrete Fn from both their basal and apical membrane domains. However, the apical secretion of Fn is specifically suppressed by progesterone.

Animals↗
PubMed1991

[Asynchronous development of the genital tract in the snail, Helix aspersa, during growth and reproduction].

During the growth of laboratory-raised Helix aspersa, the development of the albumen gland and spermoviduct was studied in relation to age, weight and different stages of reproduction such as mating and egg-laying. The results showed that the population can be divided into 2 categories because of different growth rates and asynchronous development of the genital tract. The fast-growing snails are larger and reach sexual maturity (female type maturity) in a shorter period than slow growing snails (male type maturity). During growth, the maturation of the genital tract was not directly proportional to the weight of the animal. Within each class of similar weight and age of population, 2 groups were identified; in one group, the genital tract was significantly less developed than in the other. This asynchrony of genital tract development could still be found between mating partners of the same weight, the genital tract could be 3 times smaller in one than in the other partner. However, this difference disappeared between mating and egg-laying. These observations suggest: that asynchronous development of the genital tract could be a strategy for the developing population of Helix aspersa; and that (a) mating factor(s) is (are) involved in the regulation of the growth and function of the genital tract.

Animals↗
PubMed1978

Changes at the ecto-mesodermal interface during development of the duck preen gland.

An ultrastructural investigation of the organogenesis of the duck preen gland showed variations at the ecto-mesodermal interface in the course of development. During the period of invagination, ectoderm and mesoderm were separated by a continuous basal lamina. Morphogenesis of the tubules is characterized by a preferential deposition of non-oriented collagen fibres localized at the branching sites. Direct contacts between ectodermal extensions and mesodermal cells, through gaps in the basal lamina, appeared at the end-buds after the morphogenetic pattern was established and before the onset of the glandular secretory activity. The correlation between the modification of the ecto-mesodermal interface and the differentiation of uropygial ectoderm is discussed.

Animals↗
PubMed1978

[Cytophysiologic differentiation in the epithelial region of the uropygial gland in the duck embryo Anas platyrhynchos].

The uropygial gland (preen gland), an epidermal derivative, is a bilobed, lipid-secreting gland located over the base of the tail of most birds. In the duck embryo Anas platyrhynchos, the internal branching morphogenesis of preen gland is set up at the 17th day of incubation. Each glandular lobe is made of numerous epidermal columns each of which is terminated by a bulb or end-bud. The functional differentiation of the end-buds and the development of the cellular columns into collecting ducts were investigated. The ductal epithelium, separated from the mesoderm by a continuous basal lamina, is keratinized just as in normal embryonic avian epidermis. The features which indicate glandular differentiation in the end-buds were described. Lipogenesis results from progressive cellular differentiation characterized by proliferation and development of smooth membranes. The direct ecto-mesodermal contacts, which were observed at the end-buds after the establishment of morphogenetic pattern and before the onset of glandular secretory activity, suggest that a new interaction mechanism would be required to initiate the functional differentiation.

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